Question

When a voltage measuring device is connected to ac mains, the meter shows the steady input voltage of $220V$. This means

• A. input voltage cannot be ac voltage, but a dc voltage
• B. maximum input voltage is $220V$
• C. the meter reads not V but <$V^2$> and is calibrated to read $\sqrt{<V^2>}$
• D. the pointer of the meter is stuck by some mechanical defect

Answer 1

Answer: (C)

The voltmeter connected to ac mains is calibrated to read root mean square value or virtual value of ac voltage,